The present invention relates to a circuit for providing saw-tooth current, with trace and retrace intervals, in a coil, in particular a deflection coil of a television kinescope, in which the said coil is connected to a retrace condenser and a trace condenser so as to form a deflection circuit which oscillates freely during the retrace interval; in which a first diode is connected parallel to the said deflection circuit with such polarity as to be made conductive by the saw-tooth current during a first part of the trace interval; in which the said deflection circuit is also connected parallel, by means of a second diode with such polarity as to be made conductive by the saw-tooth current during the second part of the trace interval, to a controllable switch, in particular a transistor, complete with a control electrode, connected to a source of periodic control signals which make it conductive during part of the trace interval and, finally, in which the said controllable switch is connected, by means of a first inductor, to a supply voltage source so that, during the interval in which the said switch is conductive, energy is stored in the said first inductor and later transferred, during the interval in which the said switch is not conductive, partly to the said deflection circuit, by means of a third diode, and partly to a first condenser.
A circuit of this type has already been described by A. Farina and G. Zappala in an article entitled "Self-stabilized horizontal deflection circuit", published in the 1976 No. 6 issue of the "Elettronica e Telecomunicazioni" magazine, page 237-241.
The circuit described in this article dissipates part of the energy picked up from a relatively high-voltage source (220 V) in a relatively low-voltage (12 and 24 V) auxiliary load circuit.